High blocking voltage crimped semiconductor device

Abstract

The application provides a high-breakdown-voltage press-pack semiconductor device, which can be used in the technical field of power semiconductor devices. The high-breakdown-voltage press-pack semiconductor device comprises a chip, an anode metal tube shell arranged on the anode side of the chip, and a cathode metal tube shell arranged on the cathode side of the chip; wherein the anode metal tube shell is recessed inward from the outer press surface of the chip; and / or the cathode metal tube shell is recessed inward from the outer press surface of the chip. The high-breakdown-voltage press-pack semiconductor device provided by the application has a recessed surface designed in a part of the metal tube shell in the original packaging structure of the press-pack semiconductor device, which helps to improve the breakdown voltage of the device, reduce the volume of the device, and greatly reduce the contact thermal resistance of the device.

Description

Technical Field

[0001] This application relates to the field of power semiconductor device technology, specifically to a high blocking voltage press-fit semiconductor device. Background Technology

[0002] High-power press-fit semiconductor devices are an important component of DC power transmission and distribution systems. Based on their chip structure and operating principle, they can be broadly classified into thyristors, gate turn-off thyristors (GTOs), and gate commutated thyristors (GCTs). Their common characteristic is that the main press-fit structure consists of a metal housing, a metal gasket, and a chip. Pressure is transmitted through a path of anode metal housing – anode metal gasket – chip – cathode metal gasket – cathode metal housing. The outer surfaces of the anode and cathode metal housings form the external anode and cathode press-fit surfaces of the device, and the distance between these surfaces is typically referred to as the device thickness.

[0003] Heat dissipation in press-fit semiconductor devices involves transferring heat generated by the chip directly or through metal pads from the anode and cathode surfaces to the metal package, and then through the metal package to the heat sink. This heat transfer process is hindered by the bulk thermal resistance of the chip, metal pads, and metal package, as well as the contact thermal resistance between these components. The bulk thermal resistance, influenced by the device thickness, is a significant factor affecting the overall junction-to-case thermal resistance. For package structures using gate junction rings as gate leads, the insulation distance between the anode and gate must be considered; therefore, the thickness typically depends on the edge ceramic structure, requiring a relatively large thickness, which in turn results in a higher overall junction-to-case thermal resistance. Summary of the Invention

[0004] To address the problems in the prior art, embodiments of this application provide a press-fit semiconductor device with high blocking voltage, which can at least partially solve the problems existing in the prior art.

[0005] This application discloses a high-blocking-voltage press-fit semiconductor device, comprising a chip, an anode metal shell disposed on the anode side of the chip, and a cathode metal shell disposed on the cathode side of the chip; wherein,

[0006] The outer pressure contact surface of the anode metal tube shell, away from the chip, is recessed inward;

[0007] And / or the outer pressure surface of the cathode metal casing is recessed inward away from the chip.

[0008] In some embodiments, the device further includes an anode metal flange connected to the anode metal housing, a gate connection ring connected to the gate of the chip, and a ceramic umbrella skirt hermetically connected to the anode metal flange and the gate connection ring. In some embodiments, the bottom surface of the inwardly recessed outer pressure contact surface of the anode metal housing is a plane, and the distance between the bottom surface of the inwardly recessed outer pressure contact surface and the surface of the anode metal housing near the chip is 5mm to 10mm; and / or

[0009] The bottom surface of the inwardly recessed outer pressure contact surface of the cathode metal tube shell is a plane, and the distance between the bottom surface of the inwardly recessed outer pressure contact surface and the surface of the cathode metal tube shell near the chip is 5mm to 10mm.

[0010] In some embodiments, the height of the ceramic umbrella skirt is greater than or equal to the distance between the bottom surface of the inwardly recessed outer pressure contact surface of the anode metal tube shell and the bottom surface of the inwardly recessed outer pressure contact surface of the cathode metal tube shell.

[0011] In some embodiments, the height of the ceramic umbrella skirt is 15cm or more.

[0012] In some embodiments, the maximum outer diameter of the ceramic umbrella skirt is greater than the outer diameter of the anode metal flange.

[0013] In some embodiments, the shortest distance from the outer edge of the anode metal flange around the outer edge of the ceramic umbrella skirt to the gate connection ring is greater than the air breakdown distance of the press-fit semiconductor device.

[0014] In some embodiments, the outer diameters of the collars on the ceramic umbrella skirt are the same, and the sum of the distance from the outer edge of the anode metal flange to the outer edge of the collar of the ceramic umbrella skirt closest to the anode metal flange and the distance from the outer edge of the collar of the ceramic umbrella skirt closest to the anode metal flange to the gate connection ring is greater than the air breakdown distance of the press-fit semiconductor device.

[0015] In some embodiments, the minimum surface discharge distance of the ceramic umbrella skirt is greater than the minimum surface discharge distance of the press-fit semiconductor device.

[0016] The high blocking voltage press-fit semiconductor device provided in this application reduces the size of the device and significantly lowers the contact thermal resistance by thinning a portion of the thickness of the metal casing in the original packaging structure of the press-fit semiconductor device. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0018] Figure 1 This is a schematic cross-sectional view of an existing press-fit semiconductor device.

[0019] Figure 2 This is a schematic cross-sectional view of the structure of a high blocking voltage press-fit semiconductor device provided in an embodiment of this application.

[0020] Figure 3 This is a schematic cross-sectional view of the structure of a high blocking voltage press-fit semiconductor device provided in an embodiment of this application.

[0021] Figure 4 yes Figure 3 Edge detail of a high-blocking-voltage press-fit semiconductor device. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments and their descriptions are used to explain this application, but are not intended to limit this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily arranged.

[0023] The terms “first,” “second,” etc., used in this document are not intended to specifically refer to order or sequence, nor are they used to limit this application; they are merely used to distinguish elements or operations described using the same technical terms.

[0024] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0025] The term "and / or" as used in this document includes any or all of the items mentioned.

[0026] To better understand this application, the research background of this application will be introduced in detail below.

[0027] The structural cross-section of existing press-fit semiconductor devices is as follows: Figure 1 As shown, the height of the ceramic skirt matches the height of the anode metal shell and the cathode metal shell, and the height of the ceramic skirt depends on the air breakdown distance and creepage distance between the anode metal flange and the cathode connecting ring.

[0028] like Figure 2 and Figure 3 As shown, the high blocking voltage press-fit semiconductor device 1 provided in this application embodiment includes: a chip 11, an anode metal shell 12 disposed on the anode side of the chip 11, and a cathode metal shell 13 disposed on the cathode side of the chip 11; wherein, the outer press-fit surface of the anode metal shell 12 away from the chip 11 is recessed inward, and / or the outer press-fit surface of the cathode metal shell 13 away from the chip 11 is recessed inward.

[0029] Specifically, to reduce the thickness of the metal casing of a device, the outer pressure-contact surfaces of the anode metal casing and / or the cathode metal casing in the original casing structure can be thinned by recessing. By thinning at least a portion of the thickness of the metal casing in the original packaging structure of the press-fit semiconductor device, it is helpful to reduce the size of the device and significantly reduce the contact thermal resistance of the device.

[0030] Specifically, such as Figure 2 and Figure 3 As shown, the outer pressure-contact surface of the anode metal shell 12 away from the chip 11 is a concave surface, and the outer pressure-contact surface of the cathode metal shell 13 away from the chip 11 is also a concave surface, which makes the press-fit semiconductor device 1 partially thinner. The edge protrusions of the partially thinned anode metal shell 12 and cathode metal shell 13 are connected to the anode metal flange 14 and the cathode connecting ring 17, respectively. The anode metal flange 14 is sealed to the ceramic umbrella skirt 16, the cathode connecting ring 17 is sealed to the ceramic isolation ring 19, and the gate connecting ring 15 is sealed to both the ceramic umbrella skirt 16 and the ceramic isolation ring 19. The press-fit semiconductor device 1 uses the gate connecting ring 15 as the gate lead electrode. This type of press-fit semiconductor device 1 can keep the structure and size of the ceramic umbrella skirt 16 unchanged, only shortening the distance between the outer pressure-contact surfaces of the anode and cathode.

[0031] Among them, such as Figure 2 and Figure 3 As shown, the gate connection ring 15 does not need to directly contact the gate of the chip 11. A gate contact ring 18 is provided between the gate connection ring 15 and the gate of the chip 11. The gate contact ring 18 contacts the gate of the chip 11, and the gate connection ring 15 and the gate contact ring 18 are electrically connected, indirectly realizing the electrical connection between the gate connection ring 15 and the gate of the chip 11. One end of the anode metal flange 14 is welded to the ceramic umbrella skirt 16, and the other end is welded to the anode metal shell 12; one end of the cathode connection ring 17 is welded to the ceramic isolation ring 19, and the other end is welded to the cathode metal shell 13. The welding method can be cold pressure welding or argon arc welding.

[0032] It should be understood that, Figure 2 and Figure 3The structure of the press-fit semiconductor device given is only an example. The structure of the press-fit semiconductor device using the gate connection ring as the gate lead electrode is not limited to this. Figure 2 and Figure 3 As shown in the image.

[0033] like Figure 2 and Figure 3 As shown, in some embodiments, the bottom surface of the inwardly recessed outer pressure surface of the anode metal casing 12 is a plane, and the distance between the bottom surface of the inwardly recessed outer pressure surface and the surface of the anode metal casing 12 near the chip 11 is 5mm to 10mm; and / or the bottom surface of the inwardly recessed outer pressure surface of the cathode metal casing 13 is a plane, and the distance between the bottom surface of the inwardly recessed outer pressure surface and the surface of the cathode metal casing 13 near the chip 11 is 5mm to 10mm.

[0034] In some embodiments, the distance between the bottom surface of the inwardly recessed outer pressure contact surface of the anode metal casing 12 and the surface of the anode metal casing 12 near the chip 11 is less than 7 mm; and / or the distance between the bottom surface of the inwardly recessed outer pressure contact surface of the cathode metal casing and the surface of the cathode metal casing 13 near the chip 11 is less than 7 mm.

[0035] like Figure 2 and Figure 3 As shown, in some embodiments, the height of the ceramic umbrella skirt 16 is greater than or equal to the distance between the bottom surface of the inwardly recessed outer pressure contact surface of the anode metal tube shell 12 and the bottom surface of the inwardly recessed outer pressure contact surface of the cathode metal tube shell 13.

[0036] In some embodiments, the height of the ceramic umbrella skirt 16 is 15cm or more.

[0037] like Figure 2 As shown, in some embodiments, the outer diameter of the anode metal flange 14 is greater than or equal to the maximum outer diameter of the ceramic skirt 16.

[0038] like Figure 3 and Figure 4 As shown, in some embodiments, the maximum outer diameter of the ceramic umbrella skirt 16 is greater than the outer diameter of the anode metal flange 14.

[0039] like Figure 3 and Figure 4As shown, in some embodiments, when the maximum outer diameter of the ceramic skirt 16 is greater than the outer diameter of the anode metal flange 14, the shortest distance from the outer edge of the anode metal flange 14 around the outer edge of the ceramic skirt 16 to the gate connection ring 15 is greater than the air breakdown distance of the press-fit semiconductor device 1. Specifically, considering the air breakdown distance between the anode metal flange 14 and the cathode connection ring 15, the maximum outer diameter of the anode metal flange 14 is shortened to be smaller than the maximum outer diameter of the ceramic skirt 16. This ensures that the shortest distance from the outer edge of the anode metal flange 14 around the outer edge of the ceramic skirt 16 to the gate connection ring 15 is greater than the air breakdown distance of the press-fit semiconductor device 1, thus guaranteeing the insulation between the anode metal flange 14 and the gate connection ring 15, maintaining the voltage withstand capability of the device package structure, and enabling the device to withstand higher transient and steady-state voltages.

[0040] like Figure 3 and Figure 4 As shown, in some embodiments, the outer diameters of the collars 161 on the ceramic skirt 16 are the same, and the sum of the distance a from the outer edge of the anode metal flange 14 to the outer edge of the collar 161 closest to the anode metal flange 14 on the ceramic skirt 16 and the distance b from the outer edge of the collar 161 closest to the anode metal flange 14 on the ceramic skirt 16 to the gate connection ring 15 is greater than the air breakdown distance of the press-fit semiconductor device 1.

[0041] In some embodiments, the height of the ceramic umbrella skirt 16 can be 15cm to 35cm.

[0042] like Figure 3 and Figure 4 As shown, in some embodiments, the minimum surface discharge distance of the ceramic umbrella skirt 16 is greater than the minimum surface discharge distance of the press-fit semiconductor device 1. Specifically, as... Figure 3 and Figure 4 As shown, the minimum surface discharge distance of the ceramic umbrella skirt 16 can be ensured to exceed the minimum surface discharge distance of the press-fit semiconductor device 1 by increasing the protrusion length c of each collar 161 of the ceramic umbrella skirt 16.

[0043] like Figure 2 and Figure 3 As shown, in any of the above embodiments, the distance between the bottom surface of the inwardly recessed outer pressure contact surface of the anode metal tube shell 12 and the bottom surface of the inwardly recessed outer pressure contact surface of the cathode metal tube shell 13 is less than 25 cm. Specifically, the thickness of the thinned portion of device 1 is less than 25 cm.

[0044] like Figure 2 and Figure 3As shown, in any of the above embodiments, the distance between the bottom surface of the inwardly recessed outer pressure contact surface of the anode metal shell 12 and the bottom surface of the inwardly recessed outer pressure contact surface of the cathode metal shell 13 is greater than 16 cm. Specifically, the thickness of the thinned portion of the device needs to be greater than 16 cm.

[0045] like Figure 2 and Figure 3 As shown, in any of the above embodiments, the press-fit semiconductor device 1 further includes an anode metal pad 121, which is disposed between the anode side of the chip 11 and the anode metal housing 12; and / or the press-fit semiconductor device 1 further includes a cathode metal pad 131, which is disposed between the cathode side of the chip 11 and the cathode metal housing 13. Optionally, the anode metal housing 12 and / or the cathode metal housing 13 are copper blocks, and the anode metal pad 121 and / or the cathode metal pad 131 are molybdenum sheets.

[0046] In the description of this specification, the references to terms such as "an embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A press-fit semiconductor device, characterized in that, It includes a chip, an anode metal casing disposed on the anode side of the chip, and a cathode metal casing disposed on the cathode side of the chip; wherein, The outer pressure surface of the anode metal casing away from the chip is recessed inward, and the bottom surface of the recessed outer pressure surface is a plane; and / or, the outer pressure surface of the cathode metal casing away from the chip is recessed inward, and the bottom surface of the recessed outer pressure surface is a plane. It also includes an anode metal flange connected to the anode metal shell, a gate connection ring connected to the gate of the chip, and a ceramic umbrella skirt that is hermetically connected to the anode metal flange and the gate connection ring; The height of the ceramic umbrella skirt is greater than or equal to the distance between the bottom surface of the inwardly recessed outer pressure contact surface of the anode metal tube shell and the bottom surface of the inwardly recessed outer pressure contact surface of the cathode metal tube shell.

2. The press-fit semiconductor device according to claim 1, characterized in that, The distance between the bottom surface of the inwardly recessed outer pressure contact surface of the anode metal casing and the surface of the anode metal casing near the chip is 5mm~10mm; and / or The distance between the bottom surface of the inwardly recessed outer pressure contact surface of the cathode metal tube shell and the surface of the cathode metal tube shell near the chip is 5mm~10mm.

3. The press-fit semiconductor device according to claim 1, characterized in that, The ceramic umbrella skirt is 15cm or higher in height.

4. The press-fit semiconductor device according to claim 3, characterized in that, The maximum outer diameter of the ceramic umbrella skirt is greater than the outer diameter of the anode metal flange.

5. The press-fit semiconductor device according to claim 4, characterized in that, The shortest distance from the outer edge of the anode metal flange, around the outer edge of the ceramic skirt, to the gate connection ring is greater than the air breakdown distance of the press-fit semiconductor device.

6. The press-fit semiconductor device according to claim 5, characterized in that, The outer diameters of the collars on the ceramic umbrella skirt are the same, and the sum of the distance from the outer edge of the anode metal flange to the outer edge of the collar of the ceramic umbrella skirt closest to the anode metal flange and the distance from the outer edge of the collar of the ceramic umbrella skirt closest to the anode metal flange to the gate connection ring is greater than the air breakdown distance of the press-fit semiconductor device.

7. The press-fit semiconductor device according to claim 5, characterized in that, The minimum surface discharge distance of the ceramic umbrella skirt is greater than the minimum surface discharge distance of the press-fit semiconductor device.

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